Form for casting concrete wall slab



Sept. 15, 1964 w. GARMON FORM FOR CASTING CONCRETE WALL SLAB Filed June30, 1961 THELBERT W. GARMON W INVENTOR ATTORNEY United States Patent M3,148,429 F011 FOR CASTING CGNCRETE WALL SLAB Thelhert W. Garmon, 4999Hillside Drive, Fort Worth, Tex. Filed June 30, 1961, Ser. No. 122,388 1Claim. (Cl. 25--1) This invention relates to building construction withparticular reference to precast concrete slabs used in tiltup walls, andis an improvement over my prior Patent, No. 2,858,031, issued October28, 1958.

One important object of my prior invention was to provide a means ofhandling precast concrete wall panels in a semicured or green conditionin order to substantially reduce the waiting time between pouring theslabs and erecting same on previously placed foundation piers. Thecombined form and hoisting frame described therein was designed toeliminate damaging stresses on the partly cured wall slab during theprocess of raising the slab from the horizontal to the verticalposition. To accomplish this, the flat surface on which the slab waspoured, reinforced by heavy steel beams, was kept in contact with theslab until the slab was finally braced in a vertical position. Separableelements of the form were removed before hoisting to expose the lowercorners of the slab to bear upon the foundation piers.

While this method of handling has been markedly successful, making itpossible to use larger and heavier units than by previous methods, ithas also posed the problem to the crane operator of lowering these heavyslabs onto the foundation piers gently enough to prevent damage to theexposed corners. The green concrete will carry its own weight, but thereis limited margin for the increased force of impact. In order to speedup the work and reduce the danger of broken corners it is one object ofthe present invention to strengthen these corners by providing a builtin steel bearing plate at the point of impact.

A further object of this invention is to simplify the forming process bywhich the corners of the slab are left exposed to be placed on thefoundation piers.

A further object of this invention is to introduce a steel elementbonded to the slab which can be welded to some other element of thebuilding structure.

These and other advantages will become clearly apparent from thefollowing description of which the accompanying drawing is a part, andin which:

FIGURE 1 is a perspective front view of the slab hanging in its combinederection frame and form.

FIGURE 2 is a perspective back view of the same.

FIGURE 3 is a broken elevational view of two slabs in place on thefoundation piers and a third being lowered.

FIGURE 4 is a broken perspective view of a corner of the form before theslab is poured.

FIGURE 5 is a broken end elevational view of one corner of a slab.

As already described in my prior patent, the invention includes a steelframe comprising parallel longitudinal I beams 11 with appropriate crossbracing 12. The l beams are recessed as at 13 to make room for a rigidwooden concrete form base 14 which molds one face of the slab 15. Theform base 14 has side pieces 16 and end pieces 17 temporarily attachedto its surface to define the size and thickness of the slab 15. Theouter face 13 of the slab is molded by the form base 14 and the innerface 19 is leveled off even with the upper edges of the side pieces 16and the end pieces 17. A series of holes 20 are drilled in the sidepieces 16 into which are inserted the ends of the horizontal reinforcingrods 21 3,148,429 Patented Sept. 15, 1964 which extend beyond the edgesof the slabs to bond into columns, not shown, poured into forms to bebuilt around the spaces 22 between the edges of the slabs 15' Verticalrods, not shown, are tied to the horizontal rods 21 in the usual mannerbefore pouring the concrete.

Projecting feet 23 are welded to the I beams 11 at the lower end of therecess 13 and the lower end pieces 17 of the form are cut around thesefeet in such a way that the poured concrete bears against them and willrest upon them after the end pieces 17 have been removed and the formbase 14 has been hoisted to a vertical position. Correspondingprojections 24 are located at the upper end of the recess 13 but spacedsomewhat away from the upper end of the slab 15. A hoisting yoke 25 isattached to these projections 24 which in turn is attached to a crane,not shown, by means of a hook 25a. Parallel stringers 26 are temporarilybolted to feet 23 and projections 24 to hold the slab 15 securely inplace during the tilting operation. After diagonal braces, not shown,are attached to temporary brackets 27 to hold the slab in a verticalposition on the foundation piers 28, the stringers 26 are removed andthe frame 10 and the form base 14 fall away from the slab. The form base14 has at each lower corner a rectangular notch 29 which is designed toleave the corresponding corner 30 of the slab 15 unencombered by theform base 14 where it is brought to rest on the pier 28.

This invention is directed specifically to a steel angle plate 31 whichin order to contain the concrete over the notch 29 is dropped in placeagainst the side pieces 16 and the end pieces 17 at the corner of theform as shown in FIGURE 4. One leg 32 of the angle plate 31 is the samelength as the thickness of the slab 15 while the other leg 33 is ofsufficient length to cover the notch 29. Anchor rods 34, welded to theleg 32, extend into the slab 15 far enough to bond the angle plate 31securely to the concrete after the side pieces 16 and the end pieces 17are removed.

In addition to closing the notch 29 in the form base 14 to contain theconcrete during the pouring operation, the steel angle plates 31 providea reinforced bearing for the corners 30 of the slab 15 to resist theimpact of the slab on the piers 23 when the slab is lowered into place,and thus to prevent damage to the slab and consequent rejection.

In certain types of construction it is advantageous to be able to weldconnections between the slabs 15 and other elements of the building. InFIGURES 3 and 5 optional steel plates 35 are shown resting on the top ofpiers 35 to which the angle plates 31 can be Welded. In smallerbuildings where the sides are but two or three panels long and onlyeight or nine feet high (not illustrated) the projecting rod ends 21 canbe eliminated and the space 22 between the slabs reduced to a fractionof an inch. Then the angle plates 31 on adjoining slabs can be welded toeach other to provide a continuous wall structure while the space 22 isfilled with caulking or covered with a metal strip. The top edges of theslab are tied together by a poured roof slab or a metal beam. Or ifpreferred, additional angle plates 31 can be included at the top cornersof the slab for welding, it being unnecessary to modify the form toaccomplish this.

The invention is not limited to the exemplary construction herein shownand described, but may be made in various ways within the scope of theappended claim.

What is claimed is:

A form for casting a concrete slab for a tilt-up wall comprising a flatbase for forming one surface of said slab, and larger than the slab tobe formed, side and end pieces removably attached to the upper surfaceof said base, notches at the corners of said base corresponding to thelower corners of the slab to be formed, said notches extending insidebeyond the intersection of said side pieces and said end pieces, metalangle plates detachably fitted over said notches Within said side andend pieces, one leg'of each said angle plate covering the openingdefined by the adjacent said notch and said side and end piece, Whilethe other leg rests against said end piece, and said angle plates havingintegral projecting reinforcing bars adapted to extend into the slab.

References Cited in the file of this patent UNITED STATES PATENTS

